Heat dissipating fixture



ZQU'IASQ July 9, 1935. v. L. WESTBERG HEAT DISSIPATING FIXTURE 2 Sheets-Sheet 1 Filed March 5, 1953 y 1935- v. 1.. WESTBERG ZOWASQ HEAT DISSIPATING FIXTURE Filed March 5, 1953 2 Sheets-Sheet 2 Patented July 9, 1935 2,007,489 HEAT DISSIPATING FIXTURE Vivian Luther Westberg, Chicago, Ill., assignor to Benjamin Electric Mfg. Company, Des Plaines, 111., a corporation of Illinois Application March 3, 1933, Serial No. 659,518 7 Claims. (01. 240-47) In many electric fixtures and particularly in enclosed fixtures, such as floodlights, vapor-proof and explosion-proof fixtures, theheat from the electric bulb used therein creates a very high temperature within the casing which is often sufiicient to cause a tarnishing of the reflector or entirely destroying the finish thereon. This is par ticularly true with glass reflectors which usually have a coating of silver on the outside to provide a reflecting surface. Also the electric bulb will sometimes become distorted or even explode due to the excessive heat.

It is, therefore, an object of the present invention to provide an electric fixture in which the heat from the reflector is rapidly and uniformly conducted to the casing and dissipated therefrom to the outside atmosphere, and wherein by rapidly conducting the heat from the reflector to the casing the temperature around the lamp is reduced and the life of the bulb, as well as the reflector and entire fixture, is considerably increased.

A further desirable feature of the present invention is the provision of a fixture in which is incorporated a structure which not only conducts heat rapidly to the outer casing where it may be rapidly dissipated but also allows and assists in promoting uninterrupted air circulation within 1 the fixture and over large surfaces of high heatconducting characteristics.

It is a further object to provide a heat-dissi pating device for electric fixtures which may be easily applied between a reflector and a casing and which will readily adapt itself to the shape of the reflector and casing and provide a sufiicient contact area to rapidly conduct the heat outwardly, and which will not interfere with air circulation in any fixture to which it may be applied.

The present invention also provides a heat-conducting device for electric fixtures which is of suitable material and is so constructed and applied as to combine the characteristics of high heat conductivity and sufiicient resilience to maintain the device snugly in position.

It is also an object to provide a heatdissipat ing device which is cheap to manufacture, easy to assemble in a reflector, and which readily adapts itself to various shapes of reflectors and casings within reasonable limits.

Other objects and advantages will be apparent from the specification and the appended claims.

In the drawings:

Figure 1 is a side elevation partially in section of an electric fixture incorporating one embodiment of my invention.

Fig. 2 is a plan view of a sheet metal blank or strip having suitable characteristics and from which the heat-conducting device may be formed.

Fig. 3 is a plan View of an arcuate blank from which a slightly different shaped heat-conducting means may be formed which will be adaptable to a wide angle adjustment for various types of reflectors and casings.

Fig. 4 illustrates the method of assembling a fixture incorporating one embodiment of my invention.

Fig. 5 is a transverse section through the refiector and heat-conducting device and taken on a line corresponding to line 5-5 of Fig. 1 and illustrates the distortion of the corrugations of the heat-conducting member to provide an enlarged contact area between the member and the reflector after the fixture is assembled.

Fig. 6 is a similar transverse view but taken on a line corresponding to line 66 of Fig. l and illustrates the distortion of the corrugations of the heat-conducting member to provide an enlarged area in contact with the casing.

Fig. 7 is a fragmentary detail view illustrating the blank shown in Fig. 2 after being corruated.

Fig. 8 is a perspective view of a corrugated heat-conducting cylinder before being assembled in a fixture.

Fig. 9 is a fragmentary perspective detail view illustrating the distortion of the corrugations after having been once assembled.

Referring to the drawings in detail, the embodiment illustrated comprises a so-called floodlight fixture having a casing I in which is mounted a socket 2 for supporting an electric bulb 3. A reflector 4 is mounted within the casing l and around the lamp 3 and may be of any suitable cross-sectional contour to provide the desired illumination.

In the present instance, a glass reflector is illustrated. However, it should be understood that any suitable type of reflector may be used, and the reflector may be mounted in the casing in any suitable manner. In the embodiment illustrated,

a padded ring 5 is secured around the front rim of the reflector and the ring and reflector are sup- A corrugated ring-like member 82 which is preferably of very thin aluminum, or other suit able material having heat-conducting "characteristics similar to aluminum, is supported by friction between the casing l and the reflector-4. The outer peaks of the corrugations-are distorted at lZa during the assembly to provide an enlarged area in contact with the casing is. The inner peaks of the corrugations are also distorted at M to provide a relatively large area engaging the reflector l. This ring or heat-conducting band I2 is formed by corrugating the blank shown in Fig. 2' in the manner illustrated in Fig. '7. The ends of the corrugated blank arethen overlapped and secured by means of a rivet I i 5 to form a ring or corrugated cylinder as illustrated in Fig. 8-.

As previously stated, the corrugated cylinder I2 is preferably of very thin, soft material and due to the corrugations may be readily expanded or contracted to conform generally to the angular contour of a reflector when it is forced thereon.

In assembling the device, the cylinder i2 is placed around the reflector 4, as illustrated in Fig. 4, where it assumes a conical relation conforming to the shape of the reflector. The reflector and cylinder thereon is then inserted in the casing l until the corrugated member is engaged thereby. The reflector is then forced inwardly distorting the peaks of the corrugations to provide sufiicient contact area as described previously, and the reflector is thensecured in place by means of the suitably spaced clamps 6. By this method the outer peaks of the corrugations are "forced into close contact with the casing over a comparatively large area, as illustrated in Fig. 6, and-the inner peaks of the corrugations are also forced into close contact with the outer surface of the reflector over a comparatively large area as shown in Fig. 5.

The compression of the corrugations during assemblyretains the member l2 snugly in position between the reflector and the casing and also provides an'efiicient cushioning means therebetween which is desirable with all types of reflectors and is of special importance when glass reflectors are used. i 1

It is unnecessary to provide any supporting or fastening means for the conducting'member l2 and While the blank from which the member is formed is of comparatively thin material, the corrugations provide a great number of substantially radially positioned, spaced partitions extending from the reflector to the casing whereby the heat is rapidly conductedoutwardly to the casing and dissipated therefrom. T

By the. use of this invention, it is possible to maintain the temperature of both the lamp and the reflector at a safe point Where without this means :the temperature would be too great for practical use.

The material irom'which the member I2 is formed is very thin and its position in the fixture and axial alignment therewith provides a relatively very large heat-conducting area so disposed as to avoid interrupting air circulation'within is beyond the limits of heat-conducting device in a different ble of compression the fixture. In fact, the longitudinal channels formed between the reflector and casing assist and the heat conductivity of the surfaces materially assists in maintaining a uniform air flow and eliminating cross swirls. 7

While the cylindrical embodiment previously described is adaptable to a reasonably wide angular or conical range, it is sometimes desirable to insert the heat-conducting means between a reflector and casing in which the angular relation the cylindrical construcdesirable to position the position relati-ve to the casing and reflector. In such cases, acurved blank l6 such as illustrated in Fig. 3 may be used and the corrugations or other engaging portionsinay be so formed and distributed that the resilient ring o-r'band will be conical instead of cylindrical. A band of this type is also capaand expansion, or relative p0- sitioning to adjust itself to a-variety of angular relations, and the engaging portions-"of-the cor rugations will be deformed brdepressed during tion, or in which it is the assembly ina mann'er somewhat similar to i that previously describedto provide suitable contacting areas. This type of heat conducting device is' also adaptable for use with 'a'variety of fixtures, particularly explosion-proof fixtures,

such as illustrated and described in a copending Benjamin application Serial No; 653,414 January 25, 1933.

Modifications may be in de in the embodiment illustrated and described-and I, therefore, desire to be limited only by the prior art and the scope inheat conducting. relation with said reflector and said casing; 1 v

2. A heat dissipating fixture- 0f the character described comprising a casing, a reflector in said casing, and a longitudinally corrugated cylinder of thin heat conducting material between said casing and said reflector and in axial relation therewith,the tops of the corrugations being distorted to provide increased heat transferring surfaces. v

3. In an electric fixture including a casing having a reflector therein, a heat conducting means between said reflector and said casing, said heat conducting means comprising a plurality of closely spaced and substantially radially disposed portions of relatively thin, soft material having high heat conducting characteristics, and deformed portions forming-relatively large areas contacting with said casing and said reflector.

.4. In an electric fixture having a casing and a reflector therein, means for rapidly conducting heat from the reflector. to the casing. comprising a sinuous sheet metal member between said refiector and saidcasing and having alternate portions pressed snugly against and conforming to the contacted portions of said reflector and casand contractibl'e corrugated cylinderoi thin, 7

formed as to be radially compressible to cause said portions to increase the area of contact relative to increased compression between the heated element and the casing.

7. In an electric fixture having a casing and a reflector therein, a substantially continuous sheet metal heat conductor around said reflector and in intimate heat conducting contact therewith and with said casing, said sheet metal being passages for convection currents.

VIVIAN LUTHER WESTBERG.

formed to provide a plurality of closely adjacent 10 

